A storage system typically comprises one or more storage devices into which information may be entered, and from which information may be obtained, as desired. The storage system includes a storage operating system that functionally organizes the system by, inter alia, invoking storage operations in support of a storage service implemented by the system. The storage system may be implemented in accordance with a variety of storage architectures including, but not limited to, a network-attached storage environment, a storage area network and a disk assembly directly attached to a client or host computer. The storage devices are typically disk drives organized as a disk array, wherein the term “disk” commonly describes a self-contained rotating magnetic media storage device. The term disk in this context is synonymous with hard disk drive (HDD) or direct access storage device (DASD).
The storage operating system of the storage system may implement a high-level module, such as a file system, to logically organize the information stored on volumes as a hierarchical structure of data containers, such as files and logical units. For example, each “on-disk” file may be implemented as set of data structures, i.e., disk blocks, configured to store information, such as the actual data for the file. These data blocks are organized within a volume block number (vbn) space that is maintained by the file system. The file system may also assign each data block in the file a corresponding “file offset” or file block number (fbn). The file system typically assigns sequences of fbns on a per-file basis, whereas vbns are assigned over a larger volume address space. The file system organizes the data blocks within the vbn space as a “logical volume”; each logical volume may be, although is not necessarily, associated with its own file system.
A known type of file system is a write-anywhere file system that does not overwrite data on disks. If a data block is retrieved (read) from disk into a memory of the storage system and “dirtied” (i.e., updated or modified) with new data, the data block is thereafter stored (written) to a new location on disk to optimize write performance. A write-anywhere file system may initially assume an optimal layout such that the data is substantially contiguously arranged on disks. The optimal disk layout results in efficient access operations, particularly for sequential read operations, directed to the disks. An example of a write-anywhere file system that is configured to operate on a storage system is the Write Anywhere File Layout (WAFL®) file system available from Network Appliance, Inc., Sunnyvale, Calif.
The storage system may be further configured to operate according to a client/server model of information delivery to thereby allow many clients to access data containers stored on the system. In this model, the client may comprise an application, such as a database application, executing on a computer that “connects” to the storage system over a computer network, such as a point-to-point link, shared local area network (LAN), wide area network (WAN), or virtual private network (VPN) implemented over a public network such as the Internet. Each client may request the services of the storage system by issuing file-based and block-based protocol messages (in the form of packets) to the system over the network.
Many conventional storage systems support both the Network File System (NFS) protocol and the Common Internet File System (CIFS) protocol so as to enable, for example, both conventional Microsoft Windows-based and UNIX-based clients to access data stored on the storage system. It is generally easy to obtain an NFS client and/or a CIFS client for purposes of testing a new implementation of a storage system; however, there are no presently known multi-protocol NFS and CIFS clients that are capable of interleaving commands of the two protocols directed to a single multi-protocol storage system for testing and/or debugging operations. Thus a noted problem arises for storage system developers when testing storage systems that implement multi-protocol capabilities. Such a need may arise to ensure that certain operations succeed and/or fail accordingly based on commands executed by the other protocol. For example, a range lock may be placed on a file served by a storage system using the CIFS protocol, and then a client may attempt to access the locked region of the file using the NFS protocol. Presently, a storage system vendor may acquire separate NFS and CIFS clients when implementing such a test on the storage system. However, such a multi-client testing implementation requires additional programming in order to ensure that the plurality of clients operate in a synchronous manner to ensure that operations arrive at the storage system in the desired order. This also results in increased cost by requiring the storage system vendor to obtain a plurality of storage system clients for testing purposes.